Abstract
Objectives: SARS-CoV-2 T-cell response characterization represents a crucial issue for defining the role of immune protection against COVID-19. The aim of the study was to assess the SARS-CoV-2 T-cell response in a cohort of COVID-19 convalescent patients and in a group of unexposed subjects.
Methods: SARS-CoV-2 T-cell response was quantified from peripheral blood mononuclear cells (PBMCs) of 87 COVID-19 convalescent subjects (range 7-239 days after symptom onset) and 33 unexposed donors by ex vivo ELISpot assay. Follow-up of SARS-CoV-2 T-cell response was performed in ten subjects up to 12 months after symptom onset. The role of SARS-CoV-2 specific CD4 and CD8 T cells was characterized in a group of COVID-19 convalescent subjects. Moreover, neutralizing antibodies were determined in serum samples.
Results: In 14/33 (42.4%) unexposed donors and 85/87 (97.7%) COVID-19 convalescent subjects a positive result for at least one SARS-CoV-2 antigen was observed. A positive response was observed up to 12 months after COVID-19 infection (median 246 days after symptom onset; range 118-362 days). Of note, SARS-CoV-2 T-cell response seems to be mainly mediated by CD4 T cells. A weak positive correlation was observed between Spike-specific T-cell response and neutralizing antibody titre (p 0.0028; r 2 = 0.2891) and positive SARS-CoV-2 T-cell response was observed in 8/9 (88.9%) COVID-19 convalescent subjects with undetectable SARS-CoV-2 neutralizing antibodies.
Discussion: Cross-reactive SARS-CoV-2 T-cell response in uninfected patients may be due to previous infections with other common coronaviruses. Our data suggest that long-term SARS-CoV-2 T-cell response might accompany a waning humoral response.
Keywords: ELISpot; Humoral response; Neutralizing antibodies; SARS-CoV-2; T-cell response.
【저자키워드】 SARS-CoV-2, Neutralizing antibodies, T-cell Response, Humoral response, ELISPOT, 【초록키워드】 COVID-19, neutralizing antibody, Coronaviruses, T-cell Response, Infection, Symptom, CD4, Peripheral blood, Cohort, COVID-19 infection, Patient, SARS-CoV-2 antigen, convalescent, ELISpot assay, SARS-CoV-2 neutralizing antibodies, Donor, immune protection, CD4 T cells, PBMCs, CD8 T cell, humoral, mononuclear cell, symptom onset, Ex vivo, serum samples, subject, positive correlation, positive result, titre, positive response, positive, uninfected, was performed, median, characterized, subjects, accompany, quantified, COVID-19 convalescent patient, the SARS-CoV-2, undetectable, 【제목키워드】 Control, ELISpot assay, T-cell immunity, Ex vivo, COVID-19 convalescent patient,